1. Field of the Invention
The present invention relates to an IC temperature sensor for detecting the temperature of an IC chip in a semiconductor integrated circuit (which is called IC in the following description), a power IC for audio, an IC for motor control, etc.
2. Description of the Related Art
A general IC temperature sensor has a simple, but there is about 10% dispersion in temperature coefficient with respect to an obtained voltage in a worst case because of dispersion on in element characteristics.
Japanese Patent Application Laying Open (KOKAI) No. 61-118630 shows a circuit in which the dispersion in element characteristics is considered. However, this circuit has the disadvantage that its output this circuit is changed by a change in the power voltage.
Further, there is a circuit in which there is a difference between the sizes of input transistors to cause a difference in voltage between a base and an emitter of each of the input transistors, thereby obtaining an electric current proportional to temperature. However, this circuit has the disadvantage that it cannot be easily used since its output is provided as an electric current.